1. Technical Field
The present invention relates to developing devices, image forming apparatuses, and image forming systems.
2. Related Art
Image forming apparatuses such as laser beam printers are well known. Such image forming apparatuses include, for example, a photoconductor as an example of an image bearing member for bearing a latent image, and a developing device for developing the latent image borne on the photoconductor. In the case where image signals etc. are sent out from an external device such as a host computer, the image forming apparatus positions the developing device at a developing position which is in opposition to the photoconductor. The latent image borne on the photoconductor is then developed with toner contained in the developing device, and a toner image is formed on the photoconductor. The image forming apparatus then transfers the toner image onto a medium, to ultimately form an image on the medium.
In order to achieve the above-mentioned function of developing the latent image borne on the photoconductor and other functions, the developing device has: a rotatable toner bearing roller that bears the toner and develops the latent image with the toner; and a regulation blade that abuts, with a predetermined width, against the circumferential surface of the toner bearing roller in its circumferential direction in such a manner that the longitudinal direction of the blade is along the direction of a rotation axis of the toner bearing roller, and that regulates the amount of toner borne on the toner bearing roller. The toner bearing roller develops the latent image borne on the photoconductor with the toner that is borne on the toner bearing roller and that has been regulated in amount by the regulation blade.
Further, among such toner bearing rollers, there are those that have projections and depressions (projecting sections and non-projecting sections) arranged regularly on its surface. (See, for example, JP-A-2006-259384 and JP-A-2003-57940.)
As regards the style (mode) according to which the above-mentioned regulation blade performs regulation, the so-called non-edge regulation (or flat-region-abutment regulation; a regulation style in which the tip edge, in the lateral direction and the thickness direction, of the regulation blade is not located within an abutting section having the above-mentioned predetermined width) is well known. There are cases, however, in which it is effective to adopt the so-called edge regulation (a regulation style in which the tip edge, in the lateral direction and the thickness direction, of the regulation blade is located within the abutting section having the above-mentioned predetermined width), from the viewpoint of curbing occurrence of development memory (development hysteresis), for example.
However, in cases where edge regulation is adopted, there is a possibility that, at the time the regulation blade regulates the amount of toner borne on the toner bearing roller, the tip edge of the regulation blade may enter into and collide against the non-projecting section of the toner bearing roller, thereby causing the tip edge to curl up or chip away. Such a problem is a cause of impairing the functionality of the regulation blade.